English: Phylogenetic tree based on https://en.wikipedia.org/wiki/File:Phylogenetic_tree.svg . The lowest point of the tree is the root, which symbolizes the universal common ancestor to all living beings. The tree branches out into three main groups: Bacteria (left branch, letters a to i), Archea (middle branch, letters j to p) and Eukaryota (right branch, letters q to z). Each letter corresponds to a group of organisms, listed below (in Braille on the figure):

a- Aquifex b- Thermotoga c- Bacteroides Cytophaga d- Planctomyces e- Cyanobacteria f- Proteobacteria g- Spirochetes h- Gram positives i- Green Filamentous Bacteria j- Pyrodicticum k- Thermoproteus l- T. celer m- Methanococcus n- Methanobacterium o- Methanosarcina p- Halophiles q- Entamoebae r- Slime molds s- Animals t- Fungi u- Plants v- Ciliates w- Flagellates x- Trichomonads y- Microsporidia

z- Diplomonads